SheffTechLeadership: New in a Leadership Role? How Not to Screw it Up

Inspired by a member new to a formal leadership role, we'll be chatting about the Do's and Dont's of leadership positions, especially right at the beginning when it's all shiny and new. Have you learned lessons you can share? Or are you in this position yourself? Or tell us how you'd like your own hypothetical shiny new boss to Not Screw It Up.